rbd: dynamically allocate image name

There is no need to impose a small limit the length of the rbd image
name recorded in a struct rbd_dev.  Remove the limitation by
allocating space for the image name dynamically.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

1 files changed, 13 insertions, 15 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 9b676b3b9ba0..7d4735c9dba5 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -161,8 +161,8 @@ struct rbd_device {
         spinlock_t              lock;           /* queue lock */
 
         struct rbd_image_header header;
-        char                    obj[RBD_MAX_OBJ_NAME_LEN]; /* rbd image name */
-        int                     obj_len;
+        char                    *obj; /* rbd image name */
+        size_t                  obj_len;
         char                    *obj_md_name; /* hdr nm. */
         char                    *pool_name;
         int                     pool_id;
@@ -2371,27 +2371,22 @@ static int rbd_add_parse_args(struct rbd_device *rbd_dev,
         if (!len || len >= options_size)
                 return -EINVAL;
 
+        ret = -ENOMEM;
         rbd_dev->pool_name = dup_token(&buf, NULL);
         if (!rbd_dev->pool_name)
-                return -ENOMEM;
-
-        len = copy_token(&buf, rbd_dev->obj, sizeof (rbd_dev->obj));
-        if (!len || len >= sizeof (rbd_dev->obj)) {
-                ret = -EINVAL;
                 goto out_err;
-        }
 
-        /* We have the object length in hand, save it. */
-
-        rbd_dev->obj_len = len;
+        rbd_dev->obj = dup_token(&buf, &rbd_dev->obj_len);
+        if (!rbd_dev->obj)
+                goto out_err;
 
         /* Create the name of the header object */
 
-        rbd_dev->obj_md_name = kmalloc(len + sizeof (RBD_SUFFIX), GFP_KERNEL);
-        if (!rbd_dev->obj_md_name) {
-                ret = -ENOMEM;
+        rbd_dev->obj_md_name = kmalloc(rbd_dev->obj_len
+                                                + sizeof (RBD_SUFFIX),
+                                        GFP_KERNEL);
+        if (!rbd_dev->obj_md_name)
                 goto out_err;
-        }
         sprintf(rbd_dev->obj_md_name, "%s%s", rbd_dev->obj, RBD_SUFFIX);
 
         /*
@@ -2411,6 +2406,7 @@ static int rbd_add_parse_args(struct rbd_device *rbd_dev,
 
 out_err:
         kfree(rbd_dev->obj_md_name);
+        kfree(rbd_dev->obj);
         kfree(rbd_dev->pool_name);
         rbd_dev->pool_name = NULL;
 
@@ -2514,6 +2510,7 @@ err_out_client:
 err_put_id:
         if (rbd_dev->pool_name) {
                 kfree(rbd_dev->obj_md_name);
+                kfree(rbd_dev->obj);
                 kfree(rbd_dev->pool_name);
         }
         rbd_id_put(rbd_dev);
@@ -2566,6 +2563,7 @@ static void rbd_dev_release(struct device *dev)
         /* done with the id, and with the rbd_dev */
         kfree(rbd_dev->obj_md_name);
         kfree(rbd_dev->pool_name);
+        kfree(rbd_dev->obj);
         rbd_id_put(rbd_dev);
         kfree(rbd_dev);